1. Field of the Invention
The present invention relates to a silver halide photographic light-sensitive material and a silver halide photographic emulsion used in the material and, more particularly, to a silver halide photographic emulsion and silver halide photographic light-sensitive material superior in storagebility and development dependence.
2. Description of the Related Art
The use of tabular silver halide grains (to be referred to as “tabular grains” hereinafter) to obtain a high-speed silver halide photographic light-sensitive material is well known to those skilled in the art. Methods of sensitizing these tabular grains by using epitaxial junctions are disclosed in Jpn. Pat. Appln. KOKAI Publication No. (hereinafter referred to as JP-A-)58-108526 and JP-A-59-133540. Also, applications to thinner tabular grains or to tabular grains having larger equivalent-circle diameters are disclosed in JP-A's-8-69069, 8-101472, 8-101474, 8-101475, 8-171162, 8-171163, 8-101473, 8-101476, 9-211762, and 9-211763, and U.S. Pat. Nos. 5,612,176, 5,614,359, 5,629,144, 5,631,126, 5,691,127, and 5,726,007. On the other hand, applications to tabular grains having smaller equivalent-circle diameters are disclosed in JP-A's-10-221798, 10-268457, and 10-339924. However, an epitaxial sensitization method using silver chloride as a principal constituent element is basically unstable in a light-sensitive material for photography constructed using silver iodobromide as a basic constituent element. The reason is that the solubility product of silver chloride is larger than that of silver iodide, so silver chloride readily undergoes halogen conversion. Therefore, a light-sensitive material using an epitaxial emulsion lowers its sensitivity or rises fog during storage. Additionally, the unstable solubility of an epitaxial portion varies the KBr amount during development, and this largely changes photographic properties. Hence, the method cannot be used for common light-sensitive materials for photography.